Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C1389183 (autodigestion)
 317 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Trypsin, phospholipase A2, lysolecithin or non-ionic detergent polyoxyethylene p-t-octyl phenol solutions were injected into the rat biliopancreatic duct. Histological and ultrastructural changes in the gland were studied 15 min and 3 h after the injections. The rough surfaced endoplasmic reticulum disintegrated in two ways: (1) the endoplasmic reticulum in the cell periphery was vesiculated but ribosomes were well preserved at 15 min, and (2) large, round membranous structures appeared in apical cytoplasm at 3 h. Zymogen granules disintegrated in the second type, which possibly represents autodigestion. Both types of injury lead ultimately to structureless necrosis. Lesions induced by phospholipase A2 and lysolecithin were identical. Trypsin-induced damage developed slowly and the two phases of endoplasmic reticulum disintegration were not sharply separable. Lesions caused by polyoxyethylene p-t-octyl phenol were variable at 15 min, but at 3 h the type 2 injury described above was observed. It was concluded that although the initial damage in pancreatic acinar cells may vary, necrotic changes are similar despite the injected material at the later time interval. During acute pancreatitis, the acinar cell necrosis is most probably due to the action of lysolecithin produced by the activation of phospholipase A2.
 ...
PMID:Experimental pancreatitis in the rat. Light and electron microscopical observations on early pancreatic lesions induced by intraductal injection of trypsin, phospholipase A2, lysolecithin and non-ionic detergent. 612 35

DNA endonucleases in rat liver nuclei extracts were examined by SDS-polyacrylamide gel electrophoresis followed by zymogram analysis. Four polypeptides of 120, 54, 31 and 28 kDa, which have DNA endonuclease activity, were shown to occur in the extract isolated in the presence of phenylmethanesulfonyl fluoride (PMSF), a proteinase inhibitor. Isolation without PMSF, as well as storage at -20 degrees C, or autodigestion, resulted in multiplication of active polypeptides in the extracts. Trypsin digestion led to the appearance of an active > 140 kDa polypeptide, indicating the existence of a potential endonuclease precursor in the nuclear extract.
 ...
PMID:In vitro proteolysis of endonucleases in rat liver nuclei extracts. 766 99

This study compares the susceptibility of pancreatic acinar cells and zymogen granules against oxidative injury and analyzes the mechanisms involved. Zymogen granules and acinar cells, isolated from rat pancreas, were exposed to a reaction mixture containing xanthine oxidase, hypoxanthine, and chelated iron. Cell function and viability were assessed by various techniques. Trypsin activation was quantified by an Elisa for trypsinogen activating peptide. Integrity of granules was determined by release of amylase. The reaction mixture rapidly generated radicals as assessed by deoxyribose and luminol assays. This oxidative stress caused lysis of granules in a matter of minutes but significant cell death only after some hours. Nevertheless, radicals initiated intracellular vacuolization, morphological damage to zymogen granules and mitochondria, increase in trypsinogen activating peptide, and decrease in ATP already after 5-30 min. Supramaximal caerulein concentrations also caused rapid trypsin activation. Addition of cells but not of granules reduced deoxyribose oxidation, suggesting that intact cells act as scavengers. Caerulein pretreatment only slightly increased the susceptibility of cells but markedly that of granules. In conclusion, isolated zymogen granules are markedly more susceptible to oxidative injury than intact acinar cells, in particular, in early stages of caerulein pancreatitis. The results show that oxidative stress causes a rapid trypsin activation that may contribute to cell damage by triggering autodigestion. Zymogen granules and mitochondria appear to be important targets of oxidative damage inside acinar cells. The series of intracellular events initiated by oxidative stress was similar to changes seen in early stages of pancreatitis.
 ...
PMID:Oxidative injury to isolated rat pancreatic acinar cells vs. isolated zymogen granules. 874 74

A new method combining protein chemistry with enzymes immobilized to paramagnetic beads is presented. The immobilized enzymes can substitute for regular enzymes in a number of protein chemistry protocols, resulting in faster reaction times, less sample contamination, and improved interfacing to modern procedures, like mass spectrometry. Trypsin was used as a model enzyme to test the amount of protein coupled to glass beads and the degree of autodigestion when analyzed by MALDI-MS and HPLC. Immobilization of trypsin resulted in digestions comparable with standard solution digestions using fetuin as a model substrate. Furthermore, fetuin was used to test the stability of the enzyme-coated beads. No apparent loss of enzyme activity was observed after 10 times reuse of trypsin-coated beads. Immobilization of exo- and endoglycosidases to paramagnetic beads resulted in high sensitivity, faster sequential glycosidase digestion of glycopeptides, and reduced sample contamination. All digestions could be performed in less than 24 h, when a tryptic glycopeptide from human lung proteinosis surfactant protein A was used as model compound.
 ...
PMID:Protein analysis using enzymes immobilized to paramagnetic beads. 1052 11

The spectrum of acute pancreatitis ranges from mild edematous disease to a severe necrotizing process which is usually accompanied by local or systemic complications and even mortality. Early deaths (within the first week) due to severe acute pancreatitis are generally caused by massive inflammatory responses which result in multiple organ failure. Although the exact mechanisms which trigger the inflammatory and necrotizing processes are not completely understood, it is generally accepted that autodigestion and activated leukocytes play important roles in the pathogenesis of acute pancreatitis. Proinflammatory cytokines are associated with systemic inflammatory response syndrome and multiple organ failure syndrome in acute pancreatitis. A compensatory anti-inflammatory response occurs in parallel with systemic inflammatory response syndrome. Trypsin secreted by the pancreatic acinar cells activates protease-activated receptor-2 which can result in the production of cytokines. Protease inhibitors such as aprotinin, gabexate mesilate, nafamostat mesilate, ulinastatin, etc. can inhibit the various enzymes and inflammatory response in experimental and clinical studies. Thus, protease inhibitors have been considered as a potential treatment to inhibit the pancreatic inflammation in acute pancreatitis. The beneficial effects of antiproteases on experimental severe acute pancreatitis may be, in part, due to the modulation of inflammatory cytokine responses. The effect of protease inhibitors on the inflammatory response in human acute pancreatitis deserves further study.
 ...
PMID:Action of antiproteases on the inflammatory response in acute pancreatitis. 1762 5

An aqueous extract of human placenta, used as wound healer, shows stabilization of trypsin against autodigestion as one of the peptides of the extract binds very strongly with the protease. Trypsin retains 40% of activity at constant level between 20 and 26 days in presence of the extract against complete inactivation in its absence. Inhibition of esterolytic activity and inability to react with p-nitrophenyl-p'-guanidinobenzoate, HCl, an active site directed reagent, by trypsin in presence of a peptide fraction of the extract indicated blocking of the catalytic site of the enzyme. Rayleigh scattering, size-exclusion HPLC, fluorescence resonance energy transfer, and surface plasmon resonance show that fibronectin type III-like peptide present in the extract interacts with trypsin. The peptide-trypsin complex is dissociated in presence of high concentration of substrates. Thus, regulation of trypsin activity by the placental extract is evident.
 ...
PMID:Regulation of trypsin activity by peptide fraction of an aqueous extract of human placenta used as wound healer. 2152 55

The routine proteolysis of proteins is performed in solution, but it suffers from drawbacks such as long incubation time, enzyme autodigestion, and non-reusability. Therefore we here demonstrated that trypsin could be immobilized on silver wire modified by atom transfer radical polymerization to prepare a new kind of enzyme immobilized reactor. The digestion efficiency, repeatability and recovery of the silver wire-trypsin reactor (SW-Trypsin) were evaluated by mass spectrometry (MS) analysis. Highly efficient digestion was achieved by using SW-Trypsin within only 20 min. Standard protein could be almost completely digested with sequence coverage up to 93%, which is higher than that of 79% sequence coverage obtained by in-solution digestion for 16 h. Bovine serum albumin (BSA) was digested eight times within a month by using the SW-Trypsin. The results of sequence coverage were between 89% to 97%, with an average sequence coverage of 94%, which showed that SW-Trypsin had good stability. In addition, the recovery test by using myoglobin (MYO) showed that the recovery rate was 87.67%. At last, the extract from Tengchong thermophilic bacteria was digested by SW-Trypsin in 20 min and in-solution trypsin in 16 h. The results of sequence coverages and the number of identified proteins were similar. Moreover, the ratio of the number of peptides with zero missed cleavages to the number of all identified peptides by using SW-Trypsin was higher than that by in-solution digestion. Also, the SW-Trypsin was easily removed from the digestion solution. Good performances of SW-Trypsin implied that it has a good prospect in the application in future proteomics research.
 ...
PMID:[Preparation of a trypsin immobilized reactor on silver wire modified by atom transfer radical polymer and its application in proteome identification]. 2389 35